Simple operator expression runtime

[Roger-luo]

We are missing a simple operator expression runtime to help integrating with external libraries that handles things like gate decomposition when the operator are constant folded (in the case of QASM2 compatible subset, all gates are folded into a constant operator and being inside qubit.apply or wire.apply).

Note that the operator expression should follow what we used in QEC as well as in the bloqade-pyqrack runtime. So initial integrate with pyqrack could work quickly.

We will think about the integration with cirq gate decomposition a bit later in a separate issue.

┆Issue is synchronized with this Jira Task by Unito